They are fired into the air or dropped and break in mid-air. They have the potential to spread hundreds of bomblets over large areas - covering areas as large as several football fields.

Many of the munitions fail to work properly on release and remain a threat to people long after they are fired.

About 60 per cent of the people injured by cluster bombs are not involved in conflict activities.

A third of recorded cluster munitions casualties are children.

At least 14 countries have used cluster bombs, including France, the Netherlands, Russia, the UK, the US and Saudi Arabia.

Billions of cluster bombs are held by about 76 nations. Thirty-four states have produced the weapon.

Cluster bombs were first used by German and Soviet Union forces in the second world war.

The US used significant numbers of the munitions in Cambodia, Laos and Vietnam during the 1970s.

More recently, Russia has used the weapon in Chechnya and the Sudanese government employed them during their civil war. Israel used them, and Hezbollah was accused of using them, during the Lebanon war in 2006.

The weapon caused more civilian casualties in Iraq in 2003 and Kosovo in 1999 than any other weapon system.